A multi-position connector that is mated with a cell stack of a fuel cell is disclosed in Japanese patent application JP 2013-187050 A and Japanese patent application JP 2014-154245 A. The cell stack includes a plurality of cells. The connector includes a plurality of contacts and a housing that includes cavities respectively housing the contacts. The plurality of contacts are respectively connected to electrodes of the cells of the fuel cell.
Each of the contacts in the connector disclosed in JP 2014-154245 A has a first elastic connection portion, a second elastic connection portion, and a connection base. The first elastic connection portion sandwiches a plate-like first terminal part, the second elastic portion sandwiches a plate-like second terminal part, and the connection base couples these elastic connection portions to each other. JP 2014-154245 A discloses an example in which positive electrodes or negative electrodes of the adjacent cells are connected by the connector.
Positions of the respective cells in the cell stack are mutually deviated within a tolerance range due to dimensional error of a thickness and an outer shape of each of the cells of the fuel cell, an error in assembling the stacked cells, etc. Further, in on-vehicle fuel cells, each of the cells is deflected by vibration, which causes relative displacement of the cells. Even when the positions of the respective cells on right and left ends of the cell stack are fixed, the cells disposed between the cells on the both ends may be excessively displaced due to vibration or the like in the vertical, lateral, and front-rear directions.
To absorb such positional deviations of the cells by the connector, the respective cavities of the housing that house the contacts have wide clearances or allow the electrodes of the cells to be respectively inserted deeper into contacts of the housing with respect to the contact points of the contacts.
When the clearances in the respective cavities are increased depending on the elastic deformation amounts of the contacts, the displacement of the cells can be absorbed by the elastic deformation of the contacts to some extent. This is similarly applied to the connector disclosed in JP 2014-154245 A including the elastic connection portion. The displacement, however, is accumulated in the cell thickness direction by the number of the cells relatively displaced. Therefore, absorption of the relative displacement of the cells by the elastic deformation of the contacts in the cavity is limited by a size of the connector. In addition, accumulation of the thickness tolerances of the plurality of cells may cause an excess load applied to the contacts and the cell electrodes, which may deteriorate connection reliability.
When the cell electrodes are respectively inserted deeper into the contacts as described above, the contact points respectively slide on the cell electrodes at the time of insertion or pulling-out and are likely to be worn, which may deteriorate connection reliability and inhibit downsizing of the connector. The contact points may be worn similarly in a case where distortion of the cell stack or deflection of the cells occurs in vibration and the contact points respectively slide on the cell electrodes in an in-plane direction of the cells. Sliding and deviation of the contact points from the prescribed positions of the cell electrodes can influence measurement accuracy based on signals detected through the contacts.